From Diamonds to Decay
by The Clockwork Fawn
Summary: The defeat of King Sombra is only the beginning of Celestia and Luna's troubles when they discover his daughter, Nightshade, also has strong magic. Her memory is erased and she is entrusted into the care of a loving family in the hope that she will not become like her father, but as she grows, her dangerous magic becomes a problem.
1. Chapter 1

_**Hours after the defeat of King Sombra**_

Celestia smiled as she watched Twilight and her friends board the train back to Ponyville. They all looked exhausted, having just saved the Crystal Empire from an evil tyrant, yet they still seemed to have enough energy left to congratulate Twilight on passing her test.

"She really is exceptional." Luna spoke softly, standing beside her sister.

Celestia nodded, "She is."

"Princess Celestia! Princess Luna!" A Royal Guard approached the sisters hurriedly, "Your Highnesses, I have received an urgent message from Princess Cadence, asking you to return to the Crystal Empire immediately!"

"Did she give a reason?" Celestia asked, clearly startled by the news.

"No, your Highness, only that it couldn't wait until tomorrow."

Celestia and Luna looked at each other in panic. Twilight had assured them that King Sombra was gone for good, so what could be troubling Cadence so much?

"We will leave straight away." Celestia told the Guard, fearing for Cadence's safety, "Please prepare a carriage as soon as possible."


	2. Chapter 2

"Stay away from me!" A blast of magic came shooting from behind a large formation of black crystals, almost hitting Cadence.

"I'm not here to hurt you!" Cadence explained.

"Liar! I saw what you did!" The voice was shaky.

"Please, just come out from behind there," Cadence pleaded, "I promise you'll be safe!"

The Grand Hall of the Crystal Castle fell silent for a moment. A young filly stepped out from behind the dark formations, trembling, her eyes wet with tears.

"A filly?" Cadence gasped, shocked by how powerful her magic was for a pony that young.

Shining Armour led Celestia and Luna into the hall.

"We came as soon as we got your message!" Luna explained, "Shining Armour has told us everything. You say you found her like this?"

"Yes, she was hiding behind those crystals, but I don't think she's a Crystal Pony." Cadence looked puzzled.

Luna turned to her sister after looking at the frightened filly, "Celestia, you don't think it could be-"

"I'm sure it is." Celestia answered, knowing exactly what her sister was going to say.

"But that's impossible, she's far too young!" Luna frowned, examining the pony more carefully.

Celestia sighed, "Not exactly. . ."


	3. Chapter 3

"King Sombra wasn't always the monster who you witnessed these past few days," Celestia explained to Cadence as they walked through the grounds of the Crystal Castle, "Over a thousand years ago, he was a Prince from a kingdom at the edge of Equestria. His magic was very powerful, but his heart was full of warmth and light. He visited the Crystal Empire during a great winter celebration, where he caught the eye of Princess Coralie."

"The last Crystal Princess?" Cadence asked, confused.

"Yes. They fell deeply in love almost instantly, and by the summer they were married. Soon after they became King and Queen, Coralie gave Sombra a daughter. However there was darker magic at work, and soon the Queen fell gravely ill." Celestia's voice softened as she remembered the events.

"What kind of dark magic?"

"The Empire itself was created using magic more powerful than anything you could imagine. That kind of magic is hard to control, so it was made into a physical object which would draw upon whatever it could in order to protect the city. You have to understand that this was a time of unrest in Equestria. My relationship with Luna was deteriorating by the day, allowing chaos and darkness to fall across the land since we were both too preoccupied with our own selfishness. When the Crystal Empire came under threat, the Crystal Heart drew upon the light inside its citizens – turning them almost to crystals in the process. Unable to watch her citizens suffer any longer; Queen Coralie cast a spell so that the Crystal Heart would take its power from her alone. However, the strain was too much on the Queen and soon she became very weak. Sombra tried many times to destroy the Crystal Heart but each time his efforts were in vain. The Crystal Ponies did everything they could to try and heal the Queen, but nothing could save her in the end."

"She gave her life for her citizens?" Cadence asked, concerned that, as the newly appointed Crystal Princess, she may have to do the same.

"It was a very dark time," Celestia assured Cadence, "The circumstances were extreme."

"And what about Sombra? And the child?"

"After the death of his wife, he cut off all communication from the Crystal Empire with the rest of Equestria. In his grief, darkness consumed him. He blamed the Crystal Ponies for Coralie's death, and this hatred grew, blackening his heart. He began to enslave them, treating them with contempt. As the years passed, he became crueller and more ill-tempered. The only love he had in his life was his daughter, but he kept her hidden away in the depths of the castle; fearing that the same fate would befall her as her mother. I tried to reason with him many times to free the Crystal Ponies from their slavery, but he resisted. I managed to convince my sister to aid me in putting an end to his tyranny. We defeated and banished him, but he managed to use his magic to take the Crystal Empire with him. A part of Sombra's darkness managed to corrupt my sister that day, and not long after, I was forced to banish her as well."

"How did I not know any of this?" Cadence asked.

"When the Crystal Ponies created the monument to their queen, they chose to not mention Sombra anywhere, ashamed of what he had become. The events were never recorded in any history books . . . If only all those many years ago, I hadn't let my pride get in the way. If I had reconciled with my sister instead of pushing her away, Equestria wouldn't have been in such a terrible mess in the first place!" Celestia's voice wavered as her sense of guilt grew.

Cadence tried her best to console her, "You can't blame yourself, you weren't to know how this would end!"

"If I hadn't been so foolish, that poor filly wouldn't be suffering the way she is right now."

Cadence stopped in her tracks and turned to stare at Celestia, "You're not saying that the pony in the Grand Hall is Sombra's daughter?"

"I fear that it is."

"It has been over a thousand years, yet she is just a child. Surely you're mistaken?"

"It seems that when the Empire disappeared, it became frozen in time. For Equestria, it has been a thousand years, but for them, not even a second had passed."

Cadence gasped, realising that by defeating Sombra, she had created an orphan, "No wonder she was so scared when I found her . . . What will happen to her now? She's all alone!"

"I do not know," Celestia admitted, "For now, I will take her into my care. It is the only way to keep her safe, and to keep others safe from her."


	4. Chapter 4

When Celestia and Cadence returned to the Grand Hall, they found Princess Luna amusing the filly, using her magic to create tiny stars in the air. The young pony sat patiently, staring up in wonder as hundreds of little beams of light glittered above her head.

"She seems to like you," Celestia said softly as she approached her sister, "How is she?"

Luna used her magic aura to guide the stars to the other end of the Grand Hall, causing the filly to chase after them until she was out of earshot, "She's very timid," Luna sighed, "But she says her name is Nightshade, so I believe you may be right."

Celestia watched the pony thoughtfully, "I'm sure I am, I can see it in her eyes and the way she moves, she's just like him."

"What are we going to do?" Luna looked to her sister.

"She can't stay here!" Shining Armour interrupted. He and Cadence had only just started their new life in the Crystal Empire – the last thing he wanted was for their peace to be disturbed by having to look after a child.

Cadence shot him a look before turning to Celestia, "If we need to, we will do what we can for her."

"Thank you," Celestia smiled, "But I think it would be best if she returns with us to Canterlot where we can keep a better watch on her."

Luna looked up, "Sister, don't you think she has already had enough disruption in her life already? Surely taking her from her home will only cause her more distress?"

"I'm afraid I don't know what else to do. If she stays with us in Canterlot, not only can we keep her safe, but we can keep others safe from her too. I fear that her magic is very powerful." Celestia replied, her tone incredibly serious.

Luna nodded and cautiously approached Nightshade, unsure of how exactly she should handle the situation. She sat next to her, speaking softly, "Nightshade, um, how would you like to come and live with me and my sister?"

The filly shook her head, "Where's my father?" Her eyes filled with tears.

"Listen," Luna persisted, "We're here to take care of you. If you come with us to Canterlot we can-"

"No!" Nightshade got to her feet, "I'm not going anywhere!" 

Luna tried her best to calm her, "I know you're scared but-"

"I said no!" A dark green blast of magic fired at Luna, sending her flying across the hall. 

"Luna!" Celestia ran over to her sister followed by Cadence and Shining Armour. She knew that this kind of magic had a harmful effect on Luna, "This must be stopped."

"Wait!" Luna got shakily to her hooves, "She's just a child! She's scared and confused, she doesn't know what she's doing!"

Celestia turned to Luna, realising the implication in her words. Luna saw her lot of herself in this vulnerable filly.

Stepping forward before Celestia had time to speak, Luna cast a sleep spell over Nightshade, and used her magic to make sure she didn't fall to the floor too hard. 

Cadence cleared her throat, "So, um, what now?"

Celestia seemed disheartened as she made her way over to Nightshade, "She is too dangerous; we can't allow her to remain like this."

"Can we not raise her in Canterlot and teach her to control her powers?" Luna protested.

"The risk is too great," Celestia said regretfully, "It isn't her fault, but dark magic such as this poses a great threat to the stability of Equestria. I can't allow things to return to how they were a thousand years ago."

Luna looked down, knowing her sister was right.

"Instead, I propose that we remove her magic entirely, as well as her memories. We'll place her for adoption in Ponyville – it's far enough away from here to be able to conceal the truth, but if something does go wrong, I know Twilight and her friends will be capable of handling it." Celestia wasn't sure if she was doing the right thing, but this was their only viable option.

Cadence and Luna both nodded in agreement, and Celestia leant down to the sleeping pony, shrouding her in a blinding white light. When the glow faded, Nightshade's wings and horn had disappeared, and instead a simple earth pony was left sleeping soundly on the floor.

"There is one more thing," Celestia added, "If she is to live in Ponyville, Twilight and the others must not know of her true identity. Nightshade must not know that she is different."


End file.
